Half to arthur o



No. 613,949. Patented Nov. 8, i898.

E. T. TREFETHEN.. y

DOUBLE ACTION JACK.

(Application led July 18, 1898.)

(No Model.) 2 Sheets-Sheet I.

No. 6|3,949. Patented Nov.' a, |898. E.'T. TREFETHEN.

DOUBLE ACTION JACK.

' (Application led July 1B, 139B.)

(No Model.)

2 Sheets-Sheet 2.

UNITED STATES PATENT OFFICE.

ERVIN T. TREEETIIEN, on BOSTON., MASSACHUSETTS, AssIGNoR OE ONE- I-IALF To ARTHUR o. NORTON, oF ooATIcooK, CANADA.

DOU BLE-ACTION JACK.

SPECIFICATION forming part of Letters Patent No. 613,949, dated November 8, 1898. Application filed July 18, 1898. Serial No. 686.226. (No model.)

To all whom, it may concern:

Be it known that I, ERVIN T. TREEETIIEN, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and Improved Double-Action Jack, of which the followingis a specification, reference being had to the accompanying drawings, in which- Figure l is a side elevation of my new` automatic lowering or double-action jack with the lifting-bar in its lowest position and the pawl-controller out of the path of the liftingpawls. In this View parts of the jack-standard are broken away for greater clearness and the jack is shown with the parts in position to lift. Fig. 2 is a central vertical section of the jack with the parts in the same position as in Fig. 1. Fig. 3 is a transverse sectional view at line 3 3 of Fig. l. Figs. 4 and 5 are views of opposite sides of the handle provided with reverse cams, and Figs. 6 and 7 are perspective views of the two pawls. Fig. 8 is a side elevation, partly in section, showing the lifting-bar raised and the pawlcontroller in thepath of the pawls, the parts being now in position for automatically lowering the lifting-bar. Fig. 9 is av front view of my new jack, partly in section, on line 9 9 of Fig. 8.

\ In the accompanying drawings, illustrating the principle of my invention and the best mode now known to me of applying that principle, A is the jack-standard, and B the lifting-bar. Standard A is formed with a lengthwise-extendin g recess o. to receive lifting-bar B, the recess being bridged across at a to inclose the lifting-bar and form an inclosing guideway therefor. The lifting-bar is provided with the usual head b and angularlyprojecting foot b', which bottoms, preferably, in the angularly-extending portion 0.2 of the recess a. The lifting-bar is provided on its inner face with teeth b2. The inner wall a3 of standard A extends only part way from the bottom of the standard toward the top thereof, so as to have an opeuingat a4 between the side wallsrot5 of the standard for engagement of the pawls D and D with teeth b2. In the rearwardly-extending wings a. and a7 of standard A the pawls D and D are loosely mounted on cams d and d', fast on opposite sides of the inner end portion d2 of the handle D2. Cams d and d are reversely mounted, cam d extending forwardly and cam d extending rearwardly of the journal D3, which passes through the wings and the intermediate portions of the cams and handle. Pawl D is provided toward its free end with a lateral projection d3, which extends under the free end portion of pawl D', and pawl D is also provided about opposite the journal D3 with a rearwardly-projecting lug d4, which rests on the pinf, mounted and forming part of the direction controlling frame F. Near the forward end of the pawl d a lug d5 is provided, this lug being adapted to engage the stop-rib a?, which projects from the inner face of wing a7. Pawl D is formed at its rear portion with a rearwardly-projecting lug d6, which rests on the pin j, mounted in frame F. This frame is provided with end j ournals f2 f2, which are mounted in the wings of the standard, and it is also provided with laterally-projecting endwise-chambered proa jections f3 and f3, in which the pinsfand f 'are respectively mounted. These pins are each provided with a shoulder f4 toward their upper ends, and between the shoulder f4 of each pin and the bottom of the chamber in which the pin is Vmounted there is a coiled spring f5. The bottomvof each chamber is centrally perforated, and the butt-end of each pin passes freely through the perforation and is secured in place by any suitable confining device, such as a cross-pin f6. One journal f2 is extended beyond the outer side wall of one of the wings of the standard and supports a lock-block f7, which is journaled at f8 on the extension fi of the journal f2, so as to be moved from and toward the outer face of the opposed wing of the standard, where there are a pair of abutments f1", between which the free end of the lock-block f7 is con fined when it is desired to keep the pins f and f' upright-that is, in operative position in respect to the cam-lugs d4 and d6. The lock` block is conveniently held in this position by the stress of a spring fu, mounted inits re cess f12 and bearing against an opposed sur face of the extension fg. To prevent undue wear of the cams7 their work-surfaces are preferably made by shrinking rings of appropriate quality of steel on the cam-bodies which are preferably integral with the casting that forms the handle; but the reverse construction, shown as a modication, below described maybe employed if desired. It is desirable to keep the journal from turning and consequently I provide means therefor, the preferred means consisting of a at bearing-surface on the journal-head and an opposed contacting iiat-faced lug on one of the wings of the standard. The foregoing parts constitute merely the preferred construction of jacks embodying my invention, and they may be altered in various ways without departure from my invention.

The operation of my new jack is as follows: The lifting-bar being down and the positioncontrolling frame being turned to carry pins out of contact with the cam-lugs, the free ends of both pawls gravitate toward the toothed side of the lifting-bar, all of which will be clear from Fig. l. An upward movement of handle D2 carries pawl D' upwardly into contact with one of the teeth, and the same movement of the handle retracts pawl D, so that this pawl just rests on the apex of a tooth and is ready to drop under the face of that tooth when the handle shall be lifted a little higher. Continued upward movement of the handle compels pawl D to lift the bar sufficiently to permit pawl D to pass the apex and engage the under face of the tooth on which it rests. A complete downward movement of the handle now causes pawl D to lift the bar B, and as this pawl D is pushed upward by its own cam CZ the cam d of pawl D retracts pawl Dl and causes it to pass over the apex of and drop under the face of the next lower tooth. The pawls D and D lift alternately and are alternately brought into position for lifting, one of the pawls being pushed upwardly at each upstroke of the handle, one being pushed upwardlyat each downstroke of the handle, and one being always under a tooth. To lower thelifting-bar, the position-controlling frame F is swung into position to bring its pinsfandf under the cam-lugs d* and (ZG. Supposinghandle Dg to be in its highestposition, as shown in Fig. 8, pinf is brought against lug L4 and pawl D, the spring of pin f being compressed (see Fig. 9) and its tension then lifting the free end of pawl D clear of the teeth on bar B. Pawl D is now in engagement with a tooth on the lifting-bar B. Downward movement of the handle retracts pawl D from 'the tooth and moves the free end of pawl D into engagement with a tooth, the forward movement of the pawl D carrying its lug d4 out of engagement with the pin fand the rearward movement of pawl D' carrying its lug d6 against pin f", thereby compressing the spring of that pin and causing the spring when the free end of pawl D' is out of the way of the teeth to move the free end of pawl D back out of position to engage the teeth. The lifting-bar is thereby lowered.

The cams on the handle are shown faced with hardened-steel rings; but that feature of my invention is not claimed herein, as it is claimed in another application of even date.

Vhat I claim is- 1. In a jack, the combination of a standard having a guideway for the lifting-bar; a toothed lifting-bar in said guideway; a handle fulcrumed on the standard, and provided on opposite sides with reverse cams; a pawl mounted on each cam and alternately movable into and out of engagement with teeth on the lifting-bar; a movable frame comprising a plurality of spring-controlled pins one for each pawl; and means for locking said frame in position to keep said pins in the paths of the pawls.

2. In a jack, the combination of a standard having a guideway for the lifting bar; a toothed lifting-bar in said guideway; a handle fulcrumed on the standard and provided on opposite sides with reverse cams; a pawl mounted on each cam and alternately movable into and out of engagement with teeth on the lifting-bar; a movable frame having a transverse portion journaled in the standard between the foot of the standard and the butt-ends of the pawls, said frame having endwise-chambered projections which extend laterally of the transverse portion of the frame; a yielding pin mounted in the chamber of each projection; and means for locking said frame in a position which brings said yielding pins into the paths of the butt-ends of the pawls, the pawls and pins alternately coperating during the recession of the lifting-bar, to move the pawls alternately under a tooth of the lifting-bar while the other pawl is moving to engage another tooth of the lifting-bar.

3. In a jack, the combination of a standard having a guideway for the liftingbar; a toothed lifting-bar in said guideway; a handle fulcrumed on the standard; a pair of pawls pivotally mounted on the lever at different sides of the fulcrum of the lever; a movable frame j ournaled in the standard and extending opposite the butt-ends of the pawls; means for locking said frame in its operative position during the lowering operation; and yielding devices which are between the frame and the butt-ends of the pawls during the lowering operation, andwhich then alternately connect the frame with the butt-ends of the pawls, to release one pawl from a tooth on the rack while the other pawl is moving under another tooth on the rack.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this Sth day of July, A. D. 1898.

ERVIN T. TREFETIIEN.

Witnesses:

EDWARD S. BEACH, ALICE I. CRAWFORD.

IOO

IIO 

